Various arrangements have been proposed heretofore for molding panels and other bodies. One such arrangement is disclosed in U.S. Pat. No. 3,659,986 to Gelbman. Others are shown in the following U.S. patents: U.S. Pat. No. 1,574,565, Ferguson; U.S. Pat. No. 2,298,446, White; U.S. Pat. No. 2,394,228, Barber; U.S. Pat. No. 2,466,339, Turner; U.S. Pat. No. 3,154,831, Pehoski; U.S. Pat. No. 3,193,874, Jablonski; U.S. Pat. No. 3,528,144, Haponski; U.S. Pat. No. 3,679,340, Springs; U.S. Pat. No. 3,704,979, Thiessen; U.S. Pat. No. 3,732,052, Gunia; U.S. Pat. No. 3,751,201, Kelsey; and U.S. Pat. No. 3,824,059, Heltzel.
None of these prior arrangements is entirely satisfactory for producing structural building panels of concrete. For example, the problem of achieving the homogeneity of the concrete in the finished panel that is essential to meet present-day strength requirements was not adequately solved by the previous machines. In addition, many of the prior machines did not provide entirely satisfactory solutions to the problem of stripping the concrete filling cleanly from the mold.